Device and apparatus suitable to pulsed and controlled transfer of solids in liquid phase

ABSTRACT

Finely divided particles of a brittle solid are transported by dispersing them in a transport liquid of lower density in a dispersion chamber and by feeding a series of aliquots of the dispersion from the dispersion chamber to a vessel, equipped with inlet and outlet ducts which are respectively provided with automatic control valves, when the several aliquots are subjected to increased pressure and whence the dispersed particles are expelled for transport through the outlet duct.

United States Patent Facchini.

[54] DEVICE AND APPARATUS SUITABLE TO PULSED AND CONTROLLED TRANSFER OFSOLIDS IN LIQUID PHASE [72] Inventor:

Milanese, Italy [73 Assignee: Snam Proge tti Sg A lylilan I t ly 22Filed: May 13, 1970 21 Appl.'No.: 36,765

[30] Foreign Application Priority Data May 13, 1969 Italy ..l675l A/6952 Us. 01. ..3o2/1s,417/139 [51] me c1 ..B65g 53/04 581 Field oISearch..302/14, 15, 16, 36, 53,66;

[56] References Cited UNITED STATES PATENTS 2,933,751 5/1960 Nogami ing14 i Alessandro Facchini, San Donato V [451 Sept. 12, 1972 3,206,2569/1965 Scott ..302/66 2,915,336 12/1959 Vaell ..302ll4 2,886,210 5/1959Cooper et al. ..302/l4 Primary Examiner-Even C. Blunk AssistantExaminer-11. S. Lane Attorney-Ralph M. Watson 1 [57] 1 ABSTRACT Finelydivided particles of a brittle solid are transported by dispersing themin a transport liquid of lower density in a dispersion chamber and byfeeding a series of aliquots of the dispersion from the dispersionchamber to a vessel, equipped with inlet and outlet ducts which arerespectively provided with automatic control valves, when the severalaliquots are subjected to increased pressure and whence the dispersedparticles are expelled for transport through the outlet duct.

3 Claims, 2 Drawing Figures Patnnted Sept. 12,1972 3,690,729

2 Sheets-Sheet 1 Ti ALESSANDRO FACCH/N/ Patmhed Sept 12, 1912 r3,690,729

2 Sheets-Sheet 2 J Weak/1 MME/Q =6:-

FIG. 2

ALE 55A NDRO FACCH/N/ DEVICE AND APPARATUS SUITABLE TO PULSED ANDCONTROLLED TRANSFER OF SOLIDS IN LIQUID PHASE The present inventionrelates to a new device and to an apparatus for the pulsed andcontrolled transfer of solid particles, said particles being finelydivided and brittle, dispersed in a liquid phase.

For pulsed and controlled transfer is meant the transfer effected in anintermittent way, i.e., at time intervals which may be defined at will,of amounts which may be metered at will.

Among the known systems for the transfer of solids dispersed in a liquidphase, the jet ejectors and the rotating transfer devices have to bementioned. The

first ones are based on the jet of a liquid which drags and thereforeequipped with an outlet duct in axis with the nozzle and with an inletduct of the phase to be dragged. Said device is normally utilized fordragging a gaseous or liquid fluid.

When this device is fitted to the dragging of a solid phase, it presentsthe following drawbacks;

1 It requires a noticeable amount of dragging liquid, sometimesundesired; 2) is prone to flood easily, i.e., the solid phase has thetrend to occlude the outlet duct; 3) also when this does not occur, thissystem has an unstable operation, i.e., the dragged solid flow ratetends, in a random way, to increase or to decrease. The rotatingtransfer apparatus consists in a fixed chamber, equipped with feedingduct for the solid to be dragged and with suitable discharging andcharging ducts for the dragging liquid, wherein a core rotates in whichsuitable cavities are made. In these cavities the solid phase to bedragged is collected and said solid phase is ejected therefrom afterrotation through a suitable angle.

This system too presents some drawbacks among the which we mention:

1) If the solid to be dragged is brittle it tends to break during therotation of the core; 2) if the solid has abrasive characteristics ittends to rifle the fixed chamber with subsequent drawbacks in the seal;3) as the jet operates, it has an unstable behavior. The device, whichis the subject of the present invention, obviates all theabove-mentioned drawbacks as there are no mechanical organs in motion indirect contact with the material to be dragged and its operation isperfectly stable as the amounts transferred at every pulse are quitedefinite.

Moreover, no dragging liquid is used, but, the liquid itself, whereinthe solid is dispersed, moves with it.

The dispersant liquid may be water, any organic or inorganic liquid,benzene, xylene, toluene, etc.

Apparatus for the pulsed and controlled transfer of finely divided solidparticles dispersed in a liquid phase in accordance with my invention isillustrated schematically in the accompanying drawing wherein:

FIG. 1 is an elevation of apparatus operated with a single dispersantliquid; and

FIG. 2 is an elevation of modified apparatus operating with twodispersant liquids.

FIG. 1, shown only by way of unrestrictive example, illustrates thedevice of the present invention. It consists of a hopper 1 wherein thesolid phase to be transferred is dispersed in a liquid, of a duct 5discharging into a vessel 2 having a conic bottom, of two valves 3 and 6pneumatically or electrically operated, of a three-way pressurizationvalve 4, of a valve 7 for restoring the liquid level in vessel 2, of acapacitive type probe 8 for regulating the level in vessel 2. Referencenumeral 9 indicates the discharging duct of vessel 2.

The operation of the device which is the subject of the presentinvention, consist in the following phases:

a. discharging the desired amount of solid phase mixed with liquid fromhopper 1 into vessel 2, b opening valve 3;

b. pressurization with air or with suitable inert gas, by opening valve4, of vessel 2 with the return to hopper l of the solid remained indischarging duct 5 and decantation of the solid in the conic bottom ofvessel 2 c. locking of valve 3 and opening of discharging valve 6 ofvessel 2 with transfer from the same, still pressurized, of the solidcollected in it through duct 9.

d. depressurization of vessel 2 and locking of discharging valve 6 ofthe same.

e. restoring of liquid level in vessel 2 through opening of valve 7 of asuitable feeding circuit, operated by a level regulator, preferably ofthe capacitive type, of which numeral reference 8 indicate the sensitiveelement.

Operations a, b, c, d, are effected in a pneumatic or electric way be asimple programmer.

By regulating the operations time, the flow rate of the solid phasetransfer is varied with continuity and once the operations time isfixed, said flow rate remains quite stable in the course of time.

By varying the pressure of gas introduced into vessel 2, by means ofvalve 4, it is possible to transfer the material at a certain distanceand/or at noticeable heights.

A substantial variant of the present invention is represented by thepossibility of realizing in above described tank 2, the change of theliquid in which the solid phase is dispersed initially, with anotherone, subject to choice, which has a density higher than that of theinitial liquid and lower than thatof the solid.

As examples of materials utilized in the present invention we mention:as solid phase, spherules (of about 1.3 of density) based on hydroxidesof thorium, plutonium or ammonium uranates and so on; as initial liquidphase water (density 1) :and as substituting liquid, a mixture of carbontetrachloride or of n-heptane (or n-hexane or cycloexane and so on),having density of about 1.15.

The device, according to the present invention, may be used to transfernot only spherules of compounds based on uranium, thorium and plutonium,but also any type of solid in liquid phase.

With this variant, it is not only the possible to carry the solid phase,but also to disperse the same with a new liquid to be subsequentlysubjected to other processes.

In the case of the mentioned example, it is possible to realize thedispersion of the spherules of thorium or plutonium hydroxide orammonium uranate in the above-mentioned organic mixture and theirtransfer in an apparatus in which the drying of the spherules may beeffected by means of azeotropic distillation.

Said variant is illustrated in the device of FIG. 2, which may be usedwhen the new liquid in which the solid phase is dispersed has a densityhigher than that of the initial liquid and lower than that of the solidphase to be transferred.

In FIG. 2, the following reference numerals signify:

1. collecting hopper of the solid phase dispersed into the initialliquid which has to be transferred;

2. transfer vessel;

3. discharging valve from 1) to 2);

4. pressurization valve of vessel 2;

5. discharging duct from 1) to 2) of the material to be transferred;

6. discharging valve of the material;

'7. valve for restoring the level in 2) of initial liquid;

8. sensitive element for regulating the level in 2) of said liquid;

9. valve for restoring the level in 2) of the new liquid in which thesolid phase is dispersed;

10. sensitive element for regulating the level in 2) of said liquid;

11. discharging duct of the solid phase dispersed in the new liquid.

The operation of the device of FIG. 2 coincides with the one of FIG. 1up to the above-mentioned phase (1), whereas the subsequent phases areas follows:

e. restoration of the level of the new liquid in vessel 2 by openingvalve 9 of a suitable feeding circuit, operated by a level regulator,preferably of capacitive type, whose sensitive element is indicated byreference numeral 10;

f. restoration of the initial liquid level in vessel 2 by opening valve7 of a suitable feeding circuit, operated by a level regulator,preferably of capacitive type, whose sensitive element is indicated byreference numeral 8.

From the above description, it is evident that the demixing of the solidphase from the initial liquid in the new liquid, occurs because of theirdifferent density values. As a matter of fact the solid phase collectsin vessel 2 within the new liquid as its density is higher than that ofthe same, whereas the initial liquid separates, always in vessel 2 fromthe new liquid, as its density is lower than that of the same.

Although the present invention has been described in connection with aparticular embodiment illustrated in the drawing, the inventive conceptis susceptible of numerous other applications which will occur to peopleskilled in the art. In addition, without departing from the scope of theinvention, many variations may be brought to the present invention, allthese variations being comprised in the above-mentioned main concepts.

What I claim is:

1. Apparatus for the pulsed and controlled transfer of finely dividedsolid particles dispersed in a liquid phase, comprising a hopper adaptedto hold a quantity of said disperson,

a closed transfer vessel having a conic lower end and adapted to receivedispersion from said hopper,

a feed duct leading from the bottom of the hopper to the interior of thetransfer vessel,

avalve located in said feed duct,

means for pressurizing said transfer vessel,

a discharge duct leadin from said conic bottom, a valve located in saidischarge duct,

means for actuating said valves in timed sequence,

a conduit communicating with said transfer vessel and adapted to supplya liquid thereto,

a third valve located in said conduit, and

a level regulator located in said transfer vessel adapted to actuatesaid third valve so that said liquid is maintained at a predeterminedlevel in the transfer vessel.

2; Apparatus for the pulsed and controlled transfer of finely dividedsolid particles dispersed in a liquid phase as claimed in claim 1wherein the pressurizing means communicate with the transfer vessel atits top.

3. Apparatus for the pulsed and controlled transfer of finely dividedsolid particles dispersed in a liquid phase as claimed in claim 1 andincluding a second conduit communicating with the transfer vessel andadapted to supply a second liquid thereto so that said second liquid ismaintained at a predetermined level in the transfer vessel.

1. Apparatus for the pulsed and controlled transfer of finely dividedsolid particles dispersed in a liquid phase, comprising a hopper adaptedto hold a quantity of said dispersion, a closed transfer vessel having aconic lower end and adapted to receive dispersion from said hopper, afeed duct leading from the bottom of the hopper to the interior of thetransfer vessel, a valve located in said feed duct, means forpressurizing said transfer vessel, a discharge duct leading from saidconic bottom, a valve located in said discharge duct, means foractuating said valves in timed sequence, a conduit communicating withsaid transfer vessel and adapted to supply a liquid thereto, a thirdvalve located in said conduit, and a level regulator located in saidtransfer vessel adapted to actuate said third valve so that said liquidis maintained at a predetermined level in the transfer vessel. 2.Apparatus for the pulsed and controlled transfer of finely divided solidparticles dispersed in a liquid phase as claimed in claim 1 wherein thepressurizing means communicate with the transfer vessel at its top. 3.Apparatus for the pulsed and controlled transfer of finely divided solidparticles dispersed in a liquid phase as claimed in claim 1 andincluding a second conduit communicating with the transfer vessel andadapted to supply a second liquid thereto so that said second liquid ismaintained at a predetermined level in the transfer vessel.